Limiting down the amount of calls to the database during a simple_form with multiple HABTM

Question

I am currently trying to speed up an old (3.2) Rails app and hitting an issue with way too many calls being made to the database during an edit view using simple_form

Here is the simplified setup;

class Event
  HABTM Speakers
  HABTM Sponsors

class Speaker
  belongs_to Sponsor
  HABTM Events

class Sponsor
  have_many Speakers
  HABTM Events

For an event we want to show both each potential speaker (of which there are thousands) and all the sponsors (hundreds).

For each speaker if they have a sponsor they need to show the sponsor name.

This all adds up to a lot of calls to the sponsors table, way too many.

Current Code

Right now the simple_form is set up as;

<%= simple_form_for [:admin, @event] do |f| %>
...
<%= f.association :speakers, :input_html => { :class => 'select2able' }, :label_method => :summary %>
...
<%= f.association :sponsors, :input_html => { :class => 'select2able' } %>
...

That label method is on the speaker model;

delegate :name, to: :sponsor, prefix: true, allow_nil: true

def summary
  [name, job_title, sponsor_name].compact.join ' - '
end

The @event variable is assigned in the controller with a simple

@event = Event.find params['id']

This is where I have been spending most of my time trying to improve.

What I have tried

Calling Event.includes(:speakers => :sponsor).find() I thought would help. but it hasn't at all.

I have also tried just including speaker and sponsor separately.

I have searched around for people having issues with simple_form specifically but haven't found anything. I know this is a sign of the mental structure that was made, but anything I can do to improve it without a complete re-write would be excellent.

@DavidAldridge you are right, that was a typo in my question though unfortunately! Editing now — Toby, Aug 25 '15 at 13:50

score 0 · Accepted Answer · answered Aug 26 '15 at 10:35

I was almost there with my original attempts.

This version of Rails didn't like the external includes (it executed but didn't apply anything)

The final code was a slight change where I brought the include inside the find_by.

Event.find_by_slug(params[:id], :include => [:speakers, :sponsors, :speakers => :sponsor])

Limiting down the amount of calls to the database during a simple_form with multiple HABTM

Current Code

What I have tried

1 Answers1